Form for producing artificial tooth-crowns.



E. R. STEVENSON. FORM FOR PRODUCING ARTIFICIAL TOOTH OROWNS. APPLICATION FILED 3050. so, 1909.

1,002,7'7'3. Patented Sept. 5,1911.

WITNESSES INVENTOR Z M fDW/IRD /T67El/E/V60(V ATTORNE Y8 COLUMBIA PLANOGRAPH 150.. WASHINGTON. IL c.

EDWARD RUSSELL STEVENSON, OF OAKLAND, OREGON.

FORM FOR PRODUCING ARTIFICIAL TOOTH-CROWNS.

Specification of Letters Patent.

Patented Sept. 5, 1911.

Application filed December 30, 1909. Serial No. 535,580.

a certain new and Improved Form for Pro ducing Artificial Tooth-Crowns, of which the following is a specification.

Artificial, seamless tooth-crowns, are applied to defective natural teeth for producing new artificial grinding surfaces. In manufacturing such crowns, a plate of ductile metal, preferably gold, is pressed and swaged into the required form. So-called tooth-forms are used in the production of such crowns. If a crown for a molar is to be made, a 'tooth form shaped like a molar is employed, and around it is poured some metal which is easily fusible at a low heat, and thus a counter-part die is formed, into which gold or other suitable metal plate is pressed and swaged to form the desired crown. The tooth-forms heretofore used in this operation are solid and not expansible. I have devised an improved form which is hollow and elastic, and thus adapted to be expanded by means of an inserted plug or other suitable device, whereby important advantages are attained, as will be hereinafter set forth.

In the accompanying drawingFigure 1 is a perspective view of a toothform constructed according to my invention. Fig. 2 is a perspective view of the tooth-form with a plug inserted. Fig. 3 is a longitudinal section of the form and plug shown in Fig. 2; and Fig. 4 is a perspective view of the lug.

My tooth-crown 1 is in the form of a molar, but it is of course, to be understood that it may have any other form corresponding to the tooth which is to be crowned or capped. It is provided with a cavity2which opens at the top and extends nearly to the bottom as shown in Fig. 3. The plug 8, which is constructed of some hard substance, preferably metal, is made of the same shape or form as the cavity 2, and thus adapted to be inserted and fit neatly in the same as indicated in Fig. 3. The plug is provided with a stem 3 for convenience of manipulation in inserting and removing it.

To form a die by means of the tooth-form 1, an easily fusible metal is poured around it, thus .producing a counter-part die in metal, into which the plate to form the desired crown is pressed and swaged.

My improved tooth-form being hollow is adapted to receive a plug or other device adapted for expanding it, and thus, by using different sized plugs or expanding devices, the form may be enlarged circumferentially so that several sizes of crowns may be produced by means of one form; and also the shape of the form may be changed to a certain extent, by using plugs differing more or less in contour. Forms made of solid rubber, vulcanized, or of other rigid material, cannot be expanded or altered in shape, and are thus adapted to produce only a single unvarying form of die.

What I claim is:

Thesoft-rubber form having the general external contour or shape of the body and crown of a natural tooth, and provided centrally, in its upper side, with a cavity extending nearly to the bottom of the form and adapted to receive a tapered expanding device, as and for the purpose specified.

EDWARD RUSSELL STEVENSON.

Witnesses:

H. M. STEPHENS, GEO. J. STEARNS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). 0. 

